Electrical contact structure and assembly method

ABSTRACT

According to one aspect of the disclosure, a planar substrate receives a plurality of conductive posts therein, which posts include an offset medial portion having a laterally projecting notch portion. Certain posts are arranged with their notch portions in coplanar relationship and in latching registration with an interior sidewall portion of a housing received over the posts. Accordingly, the housing provides an insulating receptacle shroud for the posts and is latchingly retained in place without a need for attachment to the substrate. The shroud is also provided with card guides connected thereto by integral hinge portions enabling alignment of, and reducing twisting and warping of, the card guides. The card guides are additionally coupled together with rails further reducing twisting and warping of the guides. The terminals are advantageously mounted in strip form for ease in manufacture and assembly to the substrate.

" United States Patent [1 1 Lynch et al.

[451 Sept. 16, 1975 ELECTRICAL CONTACT STRUCTURE AND ASSEMBLY METHOD[73] Assignee: AMP Incorporated, Harrisburg, Pa.

[22] Filed: Mar. 13, 1973 [21] Appl. No.: 340,797

Related US. Application Data [63] Continuation-impart of Ser. No.321,076, Jan. 4, 1973, abandoned, and a continuation-in-part of Ser. No.193,366, Oct. 28, 1971, abandoned, and a continuation of Ser. No.224,524, Feb. 8, 1972, abandoned, said Ser. No. 321,076, is acontinuation of Ser. No. 166,540, July 27, 1971, abandoned, said Ser.No. 224,504, is a continuation-in-part of Ser. No. 166,540, and Ser. No.193,366.

[56] References Cited UNITED STATES PATENTS 3,020,510 2/1962 Kuch 339/17L 3,365,539 1/1968 Bratschm, 339/17 R X 3,614,706 10/1971 Kukla 339/176MP X 3,660,726 5/1972 Ammon et al. 339/17 C X 3,671,917 6/1972 Ammon etal. 339/17 L 3,685,001 8/1972 Krafthefer 339/17 L 3,693,135 9/1972Vavrick et a1. 339/176 MP X 3,783,433 l/1974 Kurtz et al. 339/176 MP X3,808,578 4/1974 Hansen 339/176 MP X FOREIGN PATENTS OR APPLICATIONS1,082,958 6/1960 Germany 339/17 LM 1,079,829 8/1967 United Kingdom..339/176 MP 1,815,041 6/1970 Germany 317/101 Dl-I 2,030,906 12/1970Germany 317/101 DH OTHER PUBLICATIONS Byrnes, Injectable SolderableTerminal Pins, IBM Technical Disc. Bulletin, Vol. 9, No. 4, p. 366,September 1966.

Primary ExaminerRoy D. Frazier Assistant ExaminerLawrence J. StaabAttorney, Agent, or Firm-Gerald K. Kita [57 ABSTRACT According to oneaspect of the disclosure, a planar substrate receives a plurality ofconductive posts therein, which posts include an offset medial portionhaving a laterally projecting notch portion. Certain posts are arrangedwith their notch portions in copla nar relationship and in latchingregistration with an interior sidewall portion of a housing receivedover the posts. Accordingly, the housing provides an insulatingreceptacle shroud for the posts and is latchingly retained in placewithout a need for attachment to the substrate. The shroud is alsoprovided with card guides connected thereto by integral hinge portionsenabling alignment of, and reducing twisting and warping of, the cardguides. The card guides are additionally coupled together with railsfurther reducing twisting and warping of the guides. The terminals areadvantageously mounted in strip form for ease in manufacture andassembly to the substrate.

7 Claims, 24 Drawing Figures Pmmwsmsm 3,905,665

SHEET I 1 INVENTOR JAMES EDwAiwYNCH Y PATENTED sEP 6 ms SHEET PATENTEBSEP 165175 SHE-U PATENTEBSEPIBEB'IS 3,905,665

INVENTOR JAMES EDWARD LYNCH BY fin SHEET PATENTEI] SEP I BIBYS 3,905,665

SHEU 1 O PATENIEBSEP 16 ms SHEET 1 1 ELECTRICAL CONTACT STRUCTURE ANDASSEMBLY METHOD CROSS REFERENCES TO RELATED APPLICATIONS Thisapplication is a continuation-in-part of application Ser. No. 321,076,filed Jan. 4, 1973 and now abandoned, which is a continuation ofapplication Ser. No. 166,540, filed July 27, 1971 and now abandoned.This application is also a continuation-in-part of application Ser. No.193,366, filed Oct. 28, 1971 and now abandoned. This application is alsoa continuation of application Ser. No. 224,504, filed Feb. 8, 1972 andnow abandoned which is a continuation-in-part of application Ser. No.166,540 and of application Ser. No. 193,366.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to an insulation housing and card guide, and moreparticularly to an insulation housing and card guide for mounting on asubstrate. The present invention also relates generally to thecombination of a printed circuit board having mounted thereon aplurality of electrically conducting post-type contacts, enclosed by aremovable electrically insulating housing latchably secured to aselected contact, and also to a multi-layer printed circuit board and amethod of fabrication thereof. The present invention further relates toa method and apparatus for assembling electrically conductive posts to asubstrate, and more particularly to method and apparatus for assemblingconductive post-type contacts to a substrate which advantageouslypermits positive location and anchoring of a connector housing to thesubstrate and in enclosing relationship over the assembled contacts.

2. Description of the Prior Art The present invention satisfies the needfor a low cost electrical insulation housing for containing a pluralityof electrical terminals mounted to a substrate such as a printed circuitboard. The invention further satisfies the need for inexpensive guidesfor a card which is to be electrically connected to and disconnectedfrom the plurality of electrical terminals contained within theinsulation housing. In addition to the objective of low cost, the cardguides associated with the housing should be free of warpage andmisalignment in order to receive and permit removal of a card withoutbinding. In meeting these objectives, the insulation housing accordingto the present invention is not directly connected to the printedcircuit board or substrate. Instead, the housing is advantageouslydetachably latched to the electrical terminals mounted on the substrate.The housing thereby serves as a shroud for protecting the electricalterminals and may be readily removed when desired. Each housing includesa pair of channel guides for receiving therebetween opposed margins of acard. Each channel is connected to the housing by an integral hinge orneck portion.This feature permits the rails of flex resiliently incantilever fashion to enhance alignment thereof so that a card may bereceived between the channels without binding.

The card guide channels of a plurality of housings are connected to acommon stiffener rail to prevent warpage and twisting of the channels.

The electrical terminals to which the insulation housing is detachablylatched comprises a first conductive post portion offset from a secondconductive post portion, with a shelf portion for receiving the edge ofthe card in registration thereagainst. Adjacent to the shelf portion,each terminal is provided with a lateral notch portion. When a pluralityof the posts are mounted to the substrate, the notch portions ofselected ones of the terminals are arranged in aligned generallycoplanar relationship. The insulation housing is received over aplurality of the terminals and includes an inner linear projection orflange portion which latchingly registers within the aligned notchportions of the terminals. Accordingly, the housing is fixedly mountedto the substrate without a need for a direct mechanical connectiontherebetween. The housing is advantageously detachable from thesubstrate by resiliently flexing the sidewalls and disengaging theflange portion thereof from the notch portions of the terminals.

As a further feature, the shelf portion of each terminals to beadvantageously supplied and handled. The a carrier strip. Thus thecarriagestrip allows the terminals to bee advantageously supplied andhandled. The terminals are readily connected to the substrate byindividually detaching each terminal from its frangible stem.

The present invention is also directed to fabrication of an electricalpanel including aboard substrate into which a plurality ofelectricallyconducting post-type contacts are inserted. Post portions ofthe contacts protrude from one side of the substrate and advantageouslyreceive point-to-point electrical wiring. Other portions of the postsprotrude from the opposite side of the substrate to form electricalcontacts suitable for,

electrical registration with electrical paths of a printed circuit boardor card. In most applications, an electrically insulating connectorhousing insulates and protects the contact portions of the posts. Thehousing also must be secured on the surface of the substrate. In manycases the substrate is provided with plated circuit paths in addition tothe point-to-point wiring provided by the conducting posts.

Heretofore time consuming successive steps were required to fabricatesuch a panel. Initially the contacts were inserted individually withinthe connector housing. The contacts had to be individually latched inthe housing to prevent removal therefrom. As a practical matter, thehousing provided a plurality of individual sockets having internallatching structure for receiving and latching onto anindividual-contact. The internal structure of such a connector housingwas necessarily complex and was costly to design and fabricate. A greatdeal of time was expended to insure insertion and latching of eachindividual contact within a socket of the connector housing. Additionaltime was expended to assemble the connector housing and the retainedposts to the substrate. Fasteners such as screws and the like wererequired to attach the connector housing to the substrate surface Theposts then protrude through the apertures in the substrate to receivethe point-to-point wiring.

If it was desired to electrically connect the post-type contact toplated electrical paths of the substrate. each post portion wasseparately hand soldered to a plated path. This procedure resulted insatisfactory electrical joining, but was time consuming.

Some attempt was made to reduce the assembly time by sliding solderrings over the posts to be soldered, and simultaneously reflowing thesolder by the application of heat, inan attempt to simultaneously solderall the posts to the plated paths. Often times the reflowed solder wasof insufficient mass, or did not sufficiently wick into the substrateapertures to create a strong solder joint. This required inspection andtesting after soldering to insure electrical continuity of the solderjoints. Those joints which did not produce electrical continuity had tobe repaired by hand soldering. Also those joints which producedelectrical continuity but were structurally weak and subject to breakageat a later time also had to be replaced by hand soldering. It is notuncommon in apanel as above described to have a thousand soldered posts.If only one post in a thousand has an insufficient solder joint,representing a failure rate of 0.1%, then statistically every singlepanel would be inoperative if fabricated according to the abovedescribed assembly procedures. Thus there has been a long existing needin the prior art for a method of reliably assembling a plurality ofelectrical contacts mechanically andelectrically to a substrate andsuitable for use with a connector housing enclosing the contacts.

In the present invention, a plurality of electrically conducting postsindividually depend from a carriage strip on precise center spacings.The posts can be si multaneously assembled into apertures of a substratehaving corresponding center spacings. Each post is provided with anencircling band of solder which registers internally of a correspondingsubstrate aperture. Advantageously upon reflow of the solder bands, eachpost is reliably mechanically and electrically joined to the substrate.This assembly procedure reduces the assembly time required for insertionof individual contacts. Assembly time is further reduced bysimultaneously reflowing the solder bands of all the conduct ingcontacts desirably inserted into the substrate. This eliminates the needfor individually treating each post, either by hand soldering, or byapplying solder rings in dividually over each contact subsequent toassembly of the posts in the substrate.

Each of the contacts is attached at its terminal end to the carrierstrip with no interconnection between adjacent posts. This permitsindividual guiding of the posts into respective substrate apertureswithout undue bending or deflection of the carrier strip or theindividual posts. The carrier strip supports the contacts in mutualalignment and on desired center spacings in the board.

By providing the solder bands on the posts prior to insertion in thesubstrate, the solder bands will be located radially internally of theapertures. Each solder band is of a selected band width to providesufficient solder mass for filling the space between the lined apertureand the post inserted therein, and for the formation of filletsencircling and adhered to a conducting post at each end of a linedaperture. In addition, the solder band is precisely located internallyof the lined aperture, such that upon reflow solder will ahere along theentire length of the aperture lining. Such a joint is more reliable thana hand soldered joint or the application of solder rings to the postsafter insertion.

Soldering to the posts after insertion requires wicking of molten solderinto the lined substrate apertures. A joint produced by this wickingaction has a relatively high probability of failure. One cause offailure results from insufficient solder mass to completely fill thespace between the lined aperture and a post inserted therein, eventhough solder fillets are formed at each end of the aperture. Thepresence of the solder fillets prevents inspection for solder voidsinternally of each aperture. Another cause of failure results frominsufficient wicking action of solder internally of an aperture. Eitherof these results can produce failure, which is immediately detected bytesting for electrical continuity. Even if electrical continuity isinitially established the joint itself is structurally weak and willlater fail upon breaking of the joint when subjected to normal handlingand use.

The present invention is well suited for reducing panel assembly time,since the conducting posts are uti lized to locate and anchor andenclosing connector housing to a substrate without the need foradditional fasteners. According to one preferred embodiment, a connectorhousing is provided over the inserted contacts and is latchably joinedthereto. As an alternative, the contacts may be inserted into thesubstrate and the connector housing simultaneously. In this embodiment,reflowing of the solder bands provided on the posts is accomplished withthe connector housingin place on the substrate.

As a further feature of the invention, since the posts remain attachedto their carrier strip until positively joined to the substrate byreflowing of their solder bands, they remain in desired alignmentwithout the need for individual aligning slots in the connector housing.Accordingly, the present invention allows for the use of a connectorhousing with relatively simple interior structure. This further reducespanel assembly time since the posts need not be interfitted withinindividual slots during assembly. In addition, the costs of material andfabrication in the connector housing itself are substantially reduceddue to its relatively simple interior structure.

In addition, each of the contacts according to the present invention isprovided with a selected mass of solder adhered thereto in a selectedband width and positively located on a selected medial portion of thecontact. Each contact is further provided with structure for locating itin position on a printed circuit board, for limiting insertion thereofin a printed circuit board, as well as for positively positioning thesolder band interiorly of a plating lined hole of the board into whichthe contact is inserted.

Each contact is additionally provided with structure to which a portionof the encircling insulation housing is removably latched.

The insulation housing includes an integral latch portion. When thehousing is received over a plurality of contacts according to thepresent invention, the latch portion will resiliently register inlatching relationship on a selected one of the contacts, advantageouslysecuring the housing to the selected contact and thereby in fixedmounted position on the printed circuit board. To remove the housing, atool may be used to manually pry the resilient latch portion todisengage it from the selected contact and allow removal of the housingfrom the enclosed plurality of contacts. I

According to a feature of the present invention, when all the desirednumber of contacts are mounted in corresponding plating lined aperturesof the printed circuit board, all the solder bands of the posts aresimultaneously heated to reduce the solder bands to a molten state andreflowed by wicking action into the clearances defined between thecontacts and the apertures receiving the contacts to make positiveelectrical and mechanical connections of the contacts to the platinglined apertures. Such connection technique is disclosed in copendingapplication Ser. No. 193,366, filed Oct. 28, 1971.

Another salient feature of the present invention is practiced duringconnection of the contacts to the printed circuit board. Morespecifically, the plating lined apertures of the boards are arranged inrows, each row receiving a corresponding row of contacts insertedtherein. A common carrier strip remains attached to the individual endsof corresponding contacts in each row. The carrier strip retains thecontact ends in desired alignment during reflow of the solder, inaccordance with the disclosure of copending application Ser. No.193,366, filed Oct. 28, 1971. The medial portions of the posts in eachrow are maintained in desired alignment since they are received in thecorresponding plating lined apertures of the board. The free ends of thecontacts of each row, namely the ends which are not connected to thecarrier strip, are received in apertures of an auxiliary board orsubstrate. The apertures of the auxiliary board are on the same centerspacings as are the plating lined apertures of the printed circuitboard. Thus such free ends of the contacts of each row are maintained indesired alignment by the auxiliary board. The contacts are maintained indesired alignment by the carrier strip, the printed circuit board andthe auxiliary board while the solder bands are heated are reflowed, thensubsequently allowed to cool in order to form rigid solder jointspositively connecting individual contacts mechanically and electricallyto the plating lined holes of the printed circuit board. Upon cooling ofthe reflowed solder, rigid joints are obtained, allowing removal of theauxiliary boards and the common carrier strip portion from each row ofposts without disturbing the desired alignment of the contacts in theprinted circuit board.

According to a further feature of the present invention, the contactsprovided with solder bands may be utilized to connect together aplurality of printed circuit boards in stacked relationship. Generally,a single printed circuit board has a limited surface area whichaccordingly limits the number of plated circuit paths which can beadhered to the surface. It is common to use both a top surface and abottom surface of a printed circuit board for carrying printed circuitpaths. It is often desirable to use a second printed circuit boardadditional circuit paths which would not otherwise fit on a singleprinted circuit board already crowded with circuit paths. It is alsooften desirable to provide design changes on a second printed circuitboard.- Use of a second board obviates the need to discard the originalprinted circuit board in favor of a redesigned board. Thus, there aremany instances where two printed circuit boards are favored over the useof a single board. Where two boards are desirable, it is necessary toelectrically interconnect the circuit paths of the two boards. Accordingto the present invention, a plurality of boards may be utilized instacked relationship, with the required electrical interconnectionsbetween such boards being accomplished by a plurality of contactsaccording to the present invention received in plating lined aperturesof the boards. To provide a positive electrical interconnection betweenthe boards, the solder bands of the interconnecting contacts arereflowed and then cooled to form solder joints, thereby electrically andmechanically connecting the contacts to plating lines apertures of thestacked boards. To substantially reduce assembly time, it isadvantageous that all the contacts be inserted in the plating linedapertures of the stacked boards, and all the solder bands of theinserted contacts be simultaneously reflowed and then cooled to form theindividual solder joints. During solder reflow and cooling to form thejoints, alignment of the contacts is assured by utilizing the attachedcarrier strip and auxiliary board alignment technique as abovedescribed.

The present invention is particularly useful for fabrieating amulti-layer printed circuit board. Generally, a multi-layer boardincludes a plurality of stacked planes with circuit paths beingcarried'in a plurality of such planes. interconnections are requiredbetween circuit paths of different planes. The location of suchinterconnections between planes as wellas routing of the plated pathsthemselves are of such design complexity that automated computer designis required. In addition, fabrication of the multi-layer board must alsobe accomplished by automated techniques. The present invention permitsdesign and fabrication of a multi-layer board without the need forexpensive automated computer equipment. It therefore providesatechnology enabling the design and fabrication of complex electroniccircuit boards without a need for investing in expensive automatedequipment. The present invention accordingly enhances entry of smallcompanies into the industry of complex electronic circuitry dominated bya relatively few large companies.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide an insulating housing for a plurality of electricalterminals mounted in a substrate.

Another object of the present invention is to provide a plurality ofelectrical terminals in a substrate with an encircling insulationhousing which is not directly connected to the substrate.

Another object of the present invention is to provide a plurality ofelectrical terminals mounted in a substrate with an insulation housingencircling the termi' nals and including inner projecting portionsdetachably latched to notch portions in selected ones of the terminals.

Another object of the present invention is to provide a plurality ofelectrical terminals mounted in a substrate with an insulation housingserving as a shroud for the electrical terminals.

Another object of the present invention is to provide a plurality ofelectrical terminals mounted in a substrate and provided thereover withan insulation housing detachably latched to the terminals, which housingis provided with a pair of card guides mounted thereto for resilientcantilever action.

Another object of the present invention is to provide a housing for aplurality of electrical terminals having a pair of aligned card guidechannels connected to the housing by integral reduced neck portionsallowing resilient cantilever action of the card guide channels.

Another object of the present invention is to provide a plurality ofcard guide channels mounted for resilient cantilever action onrespective insulation housings for electrical terminals, each of whichchannels is detachably connected by a two-point support to a stiffeningrail.

Another object of the present invention is to provide an electricalterminal including a first elongated post portion, a medial portiondefining a generally planar shelf projecting laterally of thelongitudinal axis of said post, a second elongated portion dependingfrom said shelf and offset longitudinally of said post portion, and anotch portion located between the shelf portion and the second elongatedportion.

Yet another object of the present invention is to provide an electricalterminal including a conductive post portion, a medial portion defininga generally planar shelf projecting laterally of the longitudinal axisof said post portion, a second elongated portion depending from saidshelf and offset longitudinally of said post portion, a laterallyrecessed notch portion located between said shelf portion and saidelongated portion, and a frangible stem connecting said shelf portionwith acarrierstrip to which a plurality of like electrical terminals areconnected by respective frangible stems.

.Another object of the present invention is to provide a method ofassembling a substrate and a plurality of conducting post-type contacts.

Another object of the present invention is to provide a method forassembling a connector housing and a plurality of conducting post-typecontacts to a substrate having electrical paths to which the posts areelectrically joined.

Another object of the present invention is to provide apparatus in theform of electrically conducting posts, which are individually joined toa common carrier strip without any interconnection between individualposts,

and which are adapted for mass insertion within correspondingly spacedapertures of substrate.

Another object of the present invention is to provide a plurality ofconducting contact posts individually joined to a carrier strip onprecise center spacings without interconnection between individualposts, with each post provided with a band of solder mass of selectedband-width, wherein each solder band is selectively located along thelength of each contact and being reflowable to positively joint theposts to a substrate. plurality Another object of the present inventionis to provide a method for assembling a plurality of individualconducting posts simultaneously within selected apertures of a substratewhile utilizing a common carrier strip of the posts for maintaining theposts in desired alignment and center spacings until the posts arepositively secured to the substrate.

Another object of the present invention is to provide apparatus in theform of an electrically insulating housing enclosing a plurality ofelectrically conducting posts, with the posts locating and anchoring thehousing in position on a substrate, thereby eliminating the need foradditional fasteners.

A further object of the present invention is to provide appartus in theform of a combination of electrically insulating housing enclosing aplurality of electrically conducting posts, the posts mechanicallyconnecting and anchoring the housing to a substrate without the need foradditional fasteners, and the posts being maintained in desiredalignment and precise center spacings, initially by a common carrierstrip, and subsequently by being positively secured to the substrate,

with the housing being substantially free of sockets or separatingpartitions between adjacent enclosed posts.

Another object of the present invention is to provide a method forfabricating a plurality of conducting posts to a common carrier stripand utilizing the carrier strip to allow simultaneous insertion andassembly of the posts in a substrate, with the carrier strip maintainingthe posts in alignment and on selected center spacings until the postsare positively secured to the substrate.

Another object of the present invention is to provide a method forfabricating a plurality of conducting posts on a common carrier strip,using the carrier strip to maintain a plurality of posts in desiredalignment and center spacings while the posts are inserted and securedin a substrate, and utilizing the posts to mechanically connect aconnector housing to the substrate without a need for additionalfasteners.

Another object of the present invention is to provide a method andapparatus for fabricating a multi-layer circuit board wherein aplurality of stacked printed circuit boards are interconnected byelectrical contacts having solder bands thereon which are reflowedsimultaneously to form a plurality of positive solder jointsinterconnecting the contacts between selected plated paths carried bythe plurality of stacked printed circuit boards.

Another object of the present invention is to provide a method forfabricating a multi-layer circuit board wherein a stacked plurality ofseparate printed circuit boards have their circuit paths thereonselectively interconnected by corresponding electrically conductivecontacts provided with solder bands thereon which are simultaneouslyreflowed by a flowable dielectric at elevated temperature, with both thereflowed solder and the fluid dielectric being subsequently cooled to asolid state, with the solder forming positive joints securing the boardsin stacked relationship on the contacts and electrically interconnectingthe contacts between circuit paths of different boards, and with thesolid dielectric filling a clearance space between adjacent stackedboards to provide electrical insulation between the circuit paths ofadjacent boards and to encapsulate the plurality of stacked boards intoa single multi-layer board structure.

It is another object of the present invention to provide an electricallyconductive post-type contact with an adhered band of solder of selectedband width, together with structure for locating the contact in positionon a printed circuit board and for locating the solder band in a desiredposition interiorly of a plating lined aperture of the printed circuitboard, the contacting being further provided with structure to which aninsulating connector housing may be resiliently latched thereto.

- Another object of the present invention is to provide an electricallyinsulating connector housing with an integral resilient latch portionfor latchably securing the connector housing to at least one of aplurality of electrical contacts, which are mounted on a printed circuitboard or substrate and which are enclosed by the housing.

Another object of the present invention is to provide a method offabricating an assembly of a printed circuit board, a plurality ofelectrically conducting contacts and a removable electrically insulatinghousing with a latching portion resiliently latched to at least one ofthe contacts, thereby retaining the housing in desired fixed position ona printed circuit board.

Another object of the present invention is to provide a method offabricating an assembly of a printed circuit board and a plurality ofelectrically conducting posttype contacts, with the contacts beingmaintained in desired alignment by an auxiliary board or substrate and acarrier strip to which the contacts are attached during the formation.of solder joints securing the contacts mechanically and electrically tothe printed circuit board.

It is another object of the present invention to provide an insulatinghousing with integral latch portions on sidewalls of the housing forresilient latching to selected ones of a plurality of electricalcontacts, with said latches being spaced from each other to preventweakening of the housing.

It is another object of the present invention to pro vide an insulatinghousing with integral latch portions on sidewalls of the housing forresilient latching of selected ones of a plurality of electricalcontacts, with said latches being spaced from each other to preventweakening of the housing, and with said latches being spaced from thehousing ends to permit trimming off an end of the housing or to permitabutting together the ends of an adjacent pair of such housings.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of theinvention any many of the attendant advantages thereof will bereadilyobtained as the same becomes better understood by reference tothefollowing detailed description when considered inconnection with theaccompanying drawings, wherein:

FIG. 1 is a fragmentary perspective of a preferred embodiment accordingto the present invention illustrating a plurality of electrical housingsdetachably latched to electrical-terminals according to the presentinvention, with card guide channels connected to each housing byintegral, offset reduced neck portions and with the correspondingchannels of the housings being connected to a stiffener rail;

FIG. 2 is a fragmentary perspective, with parts illustrated in explodedconfiguration, illustrating a plurality of electrical terminalsaccording to the present invention, some of which are mounted to asubstrate and additional ones of which are connected by frangible stemportions to a carrier strip;

FIG. 3 is a fragmentary elevation of an insulation housing according tothe present invention illustrating a pair of card guide rails connectedby integral reduced neck portions;

FIG. 4 is a side elevation of the preferred embodiment shown in FIG. 3;

FIG. 5 is a fragmentary perspective of the preferred embodiment as shownin FIG. 1 with parts broken away and with parts in explodedconfiguration to further illustrate the details thereof;

FIG. 6 is a fragmentary perspective of first and second rows ofconducting posts individually provided with solder bands and provided onrespective common carrier strips, with a substrate shown in explodedconfiguration and having spaced apertures into which corresponding postsare inserted;

FIG. 7 is a fragmentary perspective of the preferred embodiment shown inFIG. 6 with the first and second rows of conducting pins inserted withinthe correspending apertures of a substrate, and further illustrating, aplurality of jaws for simultaneously gripping and pulling a plurality ofposts in order to seat them on the substrate and in correspondingapertures of the substrate;

FIG. 8 is a fragmentary enlarged elevation of the preferred embodimentas shown in FIG. 7 together with an insulating connector housingencircling the rows of conducting posts, and further illustrating, thesolder bands on the posts being reflowed to positively join the posts toconducting liners of the substrate apertures and to form solder filletsat each end of the corresponding substrate apertures, with the postsmechanically connecting and anchoring the housing to the substratewithout a need for additional fasteners;

FIG. 9 is a fragmentary perspective of the preferred embodiment as shownin FIG. 8 with the connector housing and the carrier strips of the firstand second rows of posts in exploded configuration to illustrate thatwhen the posts are positively joined to the substrate by reflowing thesolder bands thereof the carrier strips may be removed either prior toor subsequent to the application of the connector housing over theposts;

FIG. 10 is a fragmentary perspective with parts in section and withparts broken away and illustratingan alternative embodiment according tothe present invention including first and second rows of electricallyconducting post-type contacts each provided with a controlled band widthof solder and individually connected at a terminal end to acorresponding carrier strip together with a portion of a substrate as aconnector housing initially positioned on the substrate;

FIG. 1 1 is a fragmentary perspective of the preferred embodiment asshown in FIG. 10 with parts assembled and with parts broken away andwith parts in section to illustrate the details thereof; I

vFIG. 12 is a fragmentary perspective of the preferred embodiment asshown in FIG. 11 together with an alternative connector housing which isabsent interior slots or partitions;

FIG. 13 is an enlarged fragmentary elevation in section of a portion ofthe preferred embodiment shown in FIG. 12;

FIG. 14 is a fragmentary perspective with parts in explodedconfiguration and with parts in section illustrating the details of thecombination of a printed circuit board, a plurality of contacts mountedthereto and an insulation housing encircling the contacts and latched toat least a selected one of the contacts;

FIG. 15 is an enlarged perspective of one of the contacts of thepreferred embodiment as shown in FIG 14;

FIG. 16 is an enlarged elevation with parts in section and with parts inphantom outline of the preferred embodiment as shown in FIG. 14;

FIG. I7 is a fragmentary elevation in section of a view illustrating adrilling operation during fabrication of a pair of printed circuitboards as shown in FIG. 14;

FIG. 18 is a fragmentary enlarged perspective illustrating a pair ofprinted circuit boards fabricated according to the techniques as shownin FIG. 17 and provided with plated electrical paths and plating linedholes receiving therein electrical contacts according to the preferredembodiments shown in FIGS. 14 and 15, thereby forming an assembly inpreparation for a solder reflow operation;

FIG. 19 is a fragmentary elevation in section illustrating the assemblyshown in FIG. 18 in a fluid at elevated temperature during a solderreflow operation;

FIG. 20 is an enlarged fragmentary elevation in section illustrating theassembly of FIGS. 18 and 19 subsequent to the reflow operation as shownin FIG. 19;

FIG. 21 is an enlarged elevation in section illustrating the details ofthe preferred embodiment as shown in FIG. 14, with the insulationhousing latchably secured to at least a selected one of the contacts;

FIG. 22 is an enlarged fragmentary elevation with parts broken away andwith parts in section illustrating the details of a preferred embodimentof the insulation housing according to the presesnt invention;

FIG. 23 is an enlarged fragmentary elevation with partsbroken away andwith parts in section illustrating the details of the preferredembodiment as shown in FIG. 21; and

FIG. 24 is a fragmentary perspective of a preferred embodiment of theconnector housing as shown in FIGS. 24 and 23, with parts broken away toillustrate the details thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With more particular referenceto FIG. 1 of the drawings, there is generally indicated at l a preferredembodiment of an electrical connector and card guide according to thepresent invention. As shown with reference to FIGS. 1 and 2, a substrate2, which may comprise a printed circuit board or other suitablesubstrate, includes a plurality of apertures 4 therein which aperturesmay be lined with electrically conductive plating or solder. Theapertures 4 receive corresponding electrical terminals generallyindicated at 6. Each terminal is fabricated from a conductive metal andis characterized by a first elongated electrically conducting post 8having a generally tapered tip 10. The post 8 is integral with a medialportion 12 defining a generally planar shelf portion 14 extending andprojecting generally laterally of the longitudinal axis of the postportion 8. Each terminal 6 is further characterized by a dependingelongated electrically conducting post portion 16 generally ofrectangular or square configuration and provided with a tapered tip 18.The post portion 16 is integral with and depends from the medial portion12. The longitudinal axis of the post portion 16 is offset laterally ofthe longitudinal axis of the post portion 8 and is located generallyperpendicular to and below the shelf portion 14. A medial portion of thepost 16 is provided thereover with a band of solder 20 depositedselectively in a controlled band width. In addition, the medial portion12 of each terminal 6 is provided with a recessed lateral notch 22adjacent to the shelf portion 14 and located between the shelf portion14 and the elongated post portion 16. The notch portion 22 is of aconfiguration having an inverted generally planar wall 22 intersectinganinclined wall 24. As further shown in FIG. 2,

each terminal 6 is initially provided with an integral elongated stemportion 26 projecting vertically from the corresponding shelf portion 14and parallel to the post portion 8. Each stem portion 26 is integralwith a side margin 28 of carrier strip 30. Each stem portion 26 isfrangible generally at 32 at the intersection of the stem portion andthe corresponding shelf portion 14. As shown at 34 in FIG. 2, a somewhatirregular surface remains on the shelf portion 14 of each terminal whenit is separated from its corresponding stem. However, for purposes ofillustration the surface 34 is greatly exaggerated and the shelf portion14 remains substantially of planar configuration. Thus, the terminals 6are initially in spaced relationship along the carrier strip 30 for easein collective handling thereof. However, as shown in the FIGURE, eachindividual terminal may be advantageously handled, upon each terminalbeing frangibly separated from its corresponding stem 26 and insertedinto a corresponding aperture 4 of the substrate 2. In addition, aplurality of terminals may be inserted in the corresponding substrateapertures 4, and the carrier strip subsequently separated from theinserted terminals.

As shown in FIG. 2, a plurality of terminals 6 are thereby received incorresponding apertures 4 and arranged in a plurality of rows or regulararrays 38; The terminals are fixedly mounted to the substrate 2 byrefiowing the solder bands 20 thereof to form rigid mechanical andelectrial bonds between the substrate and the terminals, according tostandard accepted reflow soldering techniques. According to the presentinvention, the shelf portions 14 of selected terminals of a row are inaligned, generally coplanar, relationship for a purpose to behereinafter described.

With more particular reference to FIGS. 1, 3 and 4, the insulationhousings for the terminals arranged in the arrays 36 will be describedin detail. Each housing is generally indicated at 38 and includes agenerally rectangular shroud portion, defined by a pair of parallelopposed and spaced elongated sidewalls 40 and 42 and a pair of parallelspaced endwalls 44 and 46. Together the sidewalls 40 and 42 and theendwalls 44 and 46 define therebetween a single rectangular receptacleopening extending entirely through the vertical dimension of the housing38. The sidewall 42 is provided with an interior horizontal projection,or projecting flange of lip 42', extending the entire distance betweenthe endwalls 44 and 46. In similar fashion, the sidewall 40 is providedwith a horizontal projection, interior flange or lip 40 extendingbetween the endwalls 44 and 46. As further shown in FIGS. 3 and 4, takenin conjunction with FIG. 5, the endwall 44 is provided with a generallyvertically projecting elongated card guide channel generally indicatedat 48. Three sides of the channel 48 are provided with respective recessportions 50, 52 and 54 which communicate with one another and provide areduced neck configuration 56 at the intersection of the channel 48 withthe endwall 44. The neck portion is laterally offset from thelongitudinal axis of the channel portion. The channel portion 48 isadditionally provided with a longitudinal channel groove 58 extendingalong the longitudinal length of the channel 48 and in communicationwith the substantially recessed portion of a configuration determined bythe recessed portions 52', and 54 which correspond to the recessedportions 50, 52 and 54. A channel groove 58' is in parallel opposedrelationship with respect to the channel groove 58, and further is incommunication with a flared opening 62"provided in an end 60 of the channel 48. A pair of bosses 64 are provided on the end 60' which correspondto the bosses 64.

In operation, reference will be made to FIGS. 1 and 5, wherein thehousing 38 is provided over selected arrays of the terminals 6. Theinner flange of lip portions 40' and 42' of the housing sidewalls 40 and42, respectively, latchingly register within the aligned notch portions22 of the selected terminals 6. The housing 38 is fabricated from agenerally resilient plastic or other resilient electrical insulationmaterial, thereby permitting resilient flexing of of the sidewalls 40and 42 and enabling the lips 40' and 42' to resiliently latch intoregistration within the notch portions 22. All theterminals of aselected array are received into the single opening of a correspondinghousing, thereby eliminating interior webs of the housing andcontributing "to the economy of the invention. Accordingly, the housing38 is resiliently latched to the terminals 6 which in turn are fixed tothe substrate 2. The housing 38 is advantageously mounted in fixedposition with respect to the substrate 2 without a need for a directmechanical attachment therebetween. Accordingly the housing may be madeof low cost thin-wall resilient construction,

whereas if a direct mechanical attachment were required to the substrate2 a corresponding rigid construction of the housing 38 would berequired. That the housing is not directly attached to the substrateallows it to be readily removed merely by resiliently flexing thesidewalls 40 and 42 away from each other to disengage the portions 40and 42' from engagement with the notch portions 22 of the terminals 6.

As a further feature of the invention, reference is made to FIG. 1wherein the corresponding card guide channels 48 and 48' of each housing38 slidably receives the opposed side margins of a card 66. In practice,a card 66 is slidably inserted between the card guide channels 48 and48, with a plurality of electrically conducting paths 68 on the surfaceof the card being brought into electrical contact with correspond ingelectrical terminals 6 contained within thecorresponding housing 38. Theedge of the card is brought into registration on the aligned shelfportions of the corresponding terminals. It is imperative that the card66 be freely insertable and removed from the card guide channels withoutbinding. The reduced neck portions 56 and 56' act as resilientlydeformable hinges to allow the card guide channels 48 and 48 to flexresiliently in cantilever fashion and thereby relieve the bindingstresses occasioned by insertion or removal of the card 66. Thus if atendency toward binding of the card 66 is experienced, the card guidechannels 48 andv 48 will flex individually to relieve the tendencytoward binding and readily permit insertion or withdrawal of the card.In addition, the resilient cantilever action is also advantageous inthat it enables alignment of the channels 48 and 48 when the card isinitially inserted therebetween. To prevent twisting of the individualcard guide channels 48, the spaced bosses 64 are received incorresponding spaced apertures 70 of a rigid rail 72. Thus the bosses 64provide a two-point support for the end of each corresponding channel48, to prevent twisting thereof. In similar fashion, the bosses 64' arereceived in corresponding apertures of a rail 72' similar inconfiguration in the rail 72. The bosses 64 thereby provide two-pointsupports for corresponding ends of corresponding channels 48', therebypreventing twisting of the channels. Thus, the channels 48 and 48 aresupported each at two points to a common rail, with twisting of eachindividual channel thereby prevented.

Referring again to the drawings, there is shown in FIG. 6 generally at101 a plurality of conducting posttype electrical contacts having agenerally enlarged rectangular elongated medial portion 102 and adepending reduced rectangular elongated post or post portion 104integral with and depending from the medial portion 102. Each of theposts is provided with an encircling bahd of solder 108 adhered thereto.As shown, the band is adjacent to the tapered portion 106 of thecorresponding post, however'it may bedesirably located selectively alongany medial portion of the post portion 104. A solder band 108 isadvantageously applied to each of the posts in accordance with theteachings of application Ser. No: 153,315, filed June 15,

With reference yet to FIG. 6', the medial portion 102 of each of thecontacts 101 includes a pair of spaced latching tabs 109 and dependsfrom and is integral with a pair of leaf springs or fingers 1010. Theleaf springs 1010 of each contact are reversely bent into a generallyconcavo-convex configuration and depend from a single stem 1012projecting laterally ofthe longitudinal axis of an elongated carrierstrip 1.014. The'carrier strip 1014 is of the ladder type witheach'contact d'epending from a separate laterally projecting stern 1012.As shown in the FIGURE, the contacts are notably absent anyinterconnecting portions therebetween. Accordingly, the contacts arelaterally unsupported and free to move relative to one another.Additionally, the contacts are free to deflect substantially withrespect to the carrier strip 1014 and stems 1012 without overstressingthe stock material or producing permanent bends in either the contactsor the carrier strip. In addition, the carrier strip 1014 maintains theposts inmutual alignment and locates them precisely on desired centerspacings. 7

Yet with reference to FIG. 6, there is shown a portion of a substrate1016 provided with a first row of spaced apertures 1018 on centerspacings corresponding to the center spacings of the row of posts 101depending from the common carrier strip 1014. The holes 1018 areprovided with linings comprising a layer of conducting material, such asa solder or plated metal. Selected linings of selected apertures10l8'may be electrically connected to corresponding plated electricalpaths, some of which are shown at 1020,carried on the surface of thesubstrate 1016. Accordingly, the substrate 1016 may comprise a printedcircuit board or card with plating or solder lined apertureselectrically associated with circuit paths on the substrate.

Heretofore, post-type contacts were first inserted within sockets orpartitions defining channels in a connector housing fabricated from anelectrical insulation material. This was found to be advantageous sincethe connector housing retained the contacts in proper alignment andelectrically insulated from one another. As a further feature, thecontacts were lockingly latched in the connector housing, enabling thepins to "be forcibly inserted within respective apertures of a substratewithout dislodging them from the connector housing. An exemplary lockingfeature is identified by

1. In a panel having a substrate provided with metal lined apertures, aplurality of contacts having medial portions mounted in said metal linedapertures and a housing mounted on said substrate and encircling saidcontacts, the improvement comprising: bands of solder on medial portionsof said contacts joining said contacts to said metal lined apertures,sidewall portions on said housing having resilient latching meansresiliently and removably latched to selected ones of said contacts, apair of opposed elongated card guide channels projecting from saidhousing, integral reduced neck portions joining said channels incantilever fashion to said housing, said neck portiOns being resilientlydeformable to serve as resiliently deformable hinges between saidchannels and said housing, and protruding means on each of said channelsfor providing a two-point support at the terminal end of a correspondingchannel, said protruding means extending in a direction generallyparallel to the longitudinal axis of the corresponding channel.
 2. Thestructure as recited in claim 1, wherein said protruding means includesa pair of protruding bosses mutually spaced and on the terminal end of acorresponding channel.
 3. The structure as recited in claim 1, wherein,said contacts each includes an elongated first portion, a planar shelfportion extending laterally of the longitudinal axis of said firstportion and engaged on said substrate, a depending elongated postportion integral with said shelf portion and providing said medialportion joined to a corresponding metal lined aperture.
 4. The structureas recited in claim 3, wherein, said shelf portion of each contactincludes a notch for selectively receiving said latching means inlatched registration therein.
 5. In a panel having a substrate providedwith metal lined apertures, a plurality of contacts having medialportions mounted in said metal lined apertures and a housing mounted onsaid substrate and encircling said contacts, the improvement comprising:bands of solder on medial portions of said contacts joining saidcontacts to said metal lined apertures, sidewall portions on saidhousing having resilient latching means resiliently and removablylatched to selected ones of said contacts, each contact medial portionhaving an inverted shoulder and an adjacent elongated section, saidinverted shoulder having solder thereon and being engaged on saidsubstrate against a corresponding metal lined aperture, said elongatedsection having said solder thereon and being internally within acorresponding metal lined aperture, means on each contact in spacedrelationship from said substrate for selective latched receipt of saidlatching means thereon and, a clearance in a corresponding sidewallportion adjacent to said latching means to allow insertion of a tooltherein to unlatch said latching means.
 6. The structure as recited inclaim 5, wherein, said last-mentioned means includes a second invertedshoulder.
 7. The structure as recited in claim 5, wherein, saidsubstrate includes a pair of printed circuit boards having metal linedaperture sections defining said metal lined apertures, said contactmedial portions being joined internally of said aperture sections bysaid solder, and a solid dielectric sandwiched between said printedcircuit boards.